python-awips/_sources/examples/generated/Regional_Surface_Obs_Plot.rst.txt

=========================
Regional Surface Obs Plot
=========================
`Notebook <http://nbviewer.ipython.org/github/Unidata/python-awips/blob/master/examples/notebooks/Regional_Surface_Obs_Plot.ipynb>`_
Python-AWIPS Tutorial Notebook

--------------

Objectives
==========

-  Use python-awips to connect to an edex server
-  Create a plot for a regional area of the United States (Florida)
-  Define and filter data request for METAR and Synoptic surface obs
-  Use the maps database to request and draw state boundaries (no use of
   Cartopy.Feature in this example)
-  Stylize and plot surface data using Metpy

--------------

Table of Contents
-----------------

| `1
  Imports <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#imports>`__\ 
| `2 Function:
  get_cloud_cover() <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#function-get-cloud-cover>`__\ 
| `3 Function:
  make_map() <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#function-make-map>`__\ 
| `4 Function:
  extract_plotting_data() <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#function-extract-plotting-data>`__\ 
| `5 Function:
  plot_data() <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#function-plot-data>`__\ 
| `6 Initial
  Setup <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#initial-setup>`__\ 
|     `6.1 Initial EDEX
  Connection <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#initial-edex-connection>`__\ 
|     `6.2 Maps Request and
  Response <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#maps-request-and-response>`__\ 
|     `6.3 Define Geographic
  Filter <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#define-geographic-filter>`__\ 
|     `6.4 Define Time
  Filter <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#define-time-filter>`__\ 
|     `6.5 Define Common Parameters for Data
  Requests <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#define-common-parameters-for-data-requests>`__\ 
|     `6.6 Define METAR
  Request <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#define-metar-request>`__\ 
|     `6.7 Define Synoptic
  Request <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#define-synoptic-request>`__\ 
| `7 Get the
  Data! <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#get-the-data>`__\ 
|     `7.1 Get the EDEX
  Responses <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#get-the-edex-responses>`__\ 
|     `7.2 Extract Plotting
  Data <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#extract-plotting-data>`__\ 
| `8 Plot the
  Data <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#plot-the-data>`__\ 
|     `8.1 Draw the
  Region <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#draw-the-region>`__\ 
|     `8.2 Plot METAR
  Data <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#plot-metar-data>`__\ 
|     `8.3 Plot Synoptic
  Data <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#plot-synoptic-data>`__\ 
|     `8.4 Plot both METAR and Synoptic
  Data <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#plot-both-metar-and-synoptic-data>`__\ 
| `9 See
  Also <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#see-also>`__\ 
|     `9.1 Related
  Notebooks <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#related-notebooks>`__\ 
|     `9.2 Additional
  Documentation <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html#additional-documentation>`__\ 

Imports
-------

The imports below are used throughout the notebook. Note the first two
imports are coming directly from python-awips and allow us to connect to
an EDEX server, and define a timrange used for filtering the data. The
subsequent imports are for data manipulation and visualization.

.. code:: ipython3

    from awips.dataaccess import DataAccessLayer
    from dynamicserialize.dstypes.com.raytheon.uf.common.time import TimeRange
    from datetime import datetime, timedelta
    import numpy as np
    import cartopy.crs as ccrs
    from cartopy.mpl.gridliner import LONGITUDE_FORMATTER, LATITUDE_FORMATTER
    from cartopy.feature import ShapelyFeature
    from shapely.geometry import Polygon
    import matplotlib.pyplot as plt
    from metpy.units import units
    from metpy.calc import wind_components
    from metpy.plots import simple_layout, StationPlot, StationPlotLayout, sky_cover
    import warnings

`Top <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html>`__

--------------

Function: get_cloud_cover()
---------------------------

Returns the cloud coverage values as integer codes (0 through 8).

.. code:: ipython3

    def get_cloud_cover(code):
        if 'OVC' in code:
            return 8
        elif 'BKN' in code:
            return 6
        elif 'SCT' in code:
            return 4
        elif 'FEW' in code:
            return 2
        else:
            return 0

`Top <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html>`__

--------------

Function: make_map()
--------------------

In order to plot more than one image, it’s easiest to define common
logic in a function. Here, a new function called **make_map** is
defined. This function uses the `matplotlib.pyplot package
(plt) <https://matplotlib.org/3.3.3/api/_as_gen/matplotlib.pyplot.html>`__
to create a figure and axis. The geographic extent is set and lat/lon
gridlines are added for context.

.. code:: ipython3

    def make_map(bbox, proj=ccrs.PlateCarree()):
        fig, ax = plt.subplots(figsize=(16,12),subplot_kw=dict(projection=proj))
        ax.set_extent(bbox)
        gl = ax.gridlines(draw_labels=True, color='#e7e7e7')
        gl.top_labels = gl.right_labels = False
        gl.xformatter = LONGITUDE_FORMATTER
        gl.yformatter = LATITUDE_FORMATTER
        return fig, ax

`Top <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html>`__

--------------

Function: extract_plotting_data()
---------------------------------

Grab the simple variables out of the response data we have (attaching
correct units), and put them into a dictionary that we will hand the
plotting function later:

-  Get wind components from speed and direction
-  Convert cloud coverage values to integer codes [0 - 8]
-  Assign temperature, dewpoint, and sea level pressure the the correct
   units
-  Account for missing values (by using ``nan``)

.. code:: ipython3

    def extract_plotting_data(arr, datatype):
        """
        Extract all necessary data for plotting for either
        datatype: 'obs' or 'sfcobs'
        """
        
        data = dict()
        data['latitude']  = np.array(arr['latitude'])
        data['longitude'] = np.array(arr['longitude'])
        tmp = np.array(arr['temperature'], dtype=float)
        dpt = np.array(arr['dewpoint'], dtype=float)
        direction = np.array(arr['windDir'])
    
        # Suppress nan masking warnings
        warnings.filterwarnings("ignore",category =RuntimeWarning)
        
        # Account for missing values
        tmp[tmp == -9999.0] = 'nan'
        dpt[dpt == -9999.] = 'nan'
        direction[direction == -9999.0] = 'nan'
        
        data['air_pressure_at_sea_level'] = np.array(arr['seaLevelPress'])* units('mbar')
        u, v = wind_components(np.array(arr['windSpeed']) * units('knots'),
                                   direction * units.degree)
        
        data['eastward_wind'], data['northward_wind'] = u, v
        data['present_weather'] = arr['presWeather']
    
        
        # metars uses 'stationName' for its identifier and temps are in deg C
        # metars also has sky coverage
        if datatype == "obs":
            data['stid'] = np.array(arr['stationName'])
            data['air_temperature'] = tmp * units.degC
            data['dew_point_temperature'] = dpt * units.degC
            data['cloud_coverage'] = [int(get_cloud_cover(x)) for x in arr['skyCover']]
            
        # synoptic obs uses 'stationId', and temps are in Kelvin
        elif datatype == "sfcobs":
            data['stid'] = np.array(arr['stationId'])
            data['air_temperature'] = tmp * units.kelvin
            data['dew_point_temperature'] = dpt * units.kelvin
        
        return data

`Top <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html>`__

--------------

Function: plot_data()
---------------------

This function makes use of Metpy.StationPlotLayout and Metpy.StationPlot
to add all surface observation data to our plot. The logic is very
similar for both METAR and Synoptic data, so a ``datatype`` argument is
used to distinguish between which data is being drawn, and then draws
the appropriate features.

This function plots: - Wind barbs - Air temperature - Dew point
temperature - Precipitation - Cloud coverage (for METARS)

.. code:: ipython3

    def plot_data(data, title, axes, datatype):
        custom_layout = StationPlotLayout()
        custom_layout.add_barb('eastward_wind', 'northward_wind', units='knots')
        custom_layout.add_value('NW', 'air_temperature', fmt='.0f', units='degF', color='darkred')
        custom_layout.add_value('SW', 'dew_point_temperature', fmt='.0f', units='degF', color='darkgreen')
        custom_layout.add_value('E', 'precipitation', fmt='0.1f', units='inch', color='blue')
        # metars has sky coverage
        if datatype == 'obs':
            custom_layout.add_symbol('C', 'cloud_coverage', sky_cover)
        axes.set_title(title)
        stationplot = StationPlot(axes, data['longitude'], data['latitude'], clip_on=True,
                                  transform=ccrs.PlateCarree(), fontsize=10)
        custom_layout.plot(stationplot, data)

`Top <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html>`__

--------------

Initial Setup
-------------

Connect to an EDEX server and define several `new data request
objects <http://unidata.github.io/python-awips/api/IDataRequest.html>`__.

In this example we’re using multiple different datatypes from EDEX, so
we’ll create a request object for each of the following: - `The states
outlines (datatype maps) <#Define-Maps-Request>`__ - `The METAR data
(datatype obs) <#Define-METAR-Request>`__ - `The Synoptic data (datatype
sfc) <#Define-Synoptic-Request>`__

Some of the request use filters, so we’ll also create several filters
than can be used for the various data requests as well.

Initial EDEX Connection
~~~~~~~~~~~~~~~~~~~~~~~

First we establish a connection to Unidata’s public EDEX server.

.. code:: ipython3

    # EDEX connection
    edexServer = "edex-cloud.unidata.ucar.edu"
    DataAccessLayer.changeEDEXHost(edexServer)

Maps Request and Response
~~~~~~~~~~~~~~~~~~~~~~~~~

The maps data request will give us data to draw our state outlines of
interest (Florida and its neighboring states). We will retrieve the data
response object here so we can create a geographic filter for the METAR
and Synoptic data requests.

.. code:: ipython3

    # Define the maps request
    maps_request = DataAccessLayer.newDataRequest('maps')
    # filter for multiple states
    maps_request.addIdentifier('table', 'mapdata.states')
    maps_request.addIdentifier('geomField', 'the_geom')
    maps_request.addIdentifier('inLocation', 'true')
    maps_request.addIdentifier('locationField', 'state')
    maps_request.setParameters('state','name','lat','lon')
    maps_request.setLocationNames('FL','GA','MS','AL','SC','LA')
    maps_response = DataAccessLayer.getGeometryData(maps_request)
    print("Found " + str(len(maps_response)) + " MultiPolygons")


.. parsed-literal::

    Found 6 MultiPolygons


Define Geographic Filter
~~~~~~~~~~~~~~~~~~~~~~~~

The previous EDEX request limited the data by using a **parameter** for
the maps database called **state**. We can take the results from that
filter and get a geographic **envelope** based on the Florida polygon
that was returned from the previous cell.

   **Warning**: Without such a filter you may be requesting many tens of
   thousands of records.

.. code:: ipython3

    # Append each geometry to a numpy array
    states = np.array([])
    for ob in maps_response:
        print(ob.getString('name'), ob.getString('state'), ob.getNumber('lat'), ob.getNumber('lon'))
        states = np.append(states,ob.getGeometry())
        # if this is Florida grab geographic info
        if ob.getString('name') == "Florida":
            bounds = ob.getGeometry().bounds
            fl_lat = ob.getNumber('lat')
            fl_lon = ob.getNumber('lon')
    
    if bounds is None:
        print("Error, no record found for Florida!")
    
    else:    
        # buffer our bounds by +/i degrees lat/lon
        bbox=[bounds[0]-3,bounds[2]+3,bounds[1]-1.5,bounds[3]+1.5]
    
        # Create envelope geometry
        envelope = Polygon([(bbox[0],bbox[2]),(bbox[0],bbox[3]),
                            (bbox[1], bbox[3]),(bbox[1],bbox[2]),
                            (bbox[0],bbox[2])])
        
    print(envelope)


.. parsed-literal::

    Florida FL 28.67402 -82.50934
    Georgia GA 32.65155 -83.44848
    Louisiana LA 31.0891 -92.02905
    Alabama AL 32.79354 -86.82676
    Mississippi MS 32.75201 -89.66553
    South Carolina SC 33.93574 -80.89899
    POLYGON ((-90.63429260299995 23.02105161600002, -90.63429260299995 32.50101280200016, -77.03199876199994 32.50101280200016, -77.03199876199994 23.02105161600002, -90.63429260299995 23.02105161600002))


Define Time Filter
~~~~~~~~~~~~~~~~~~

Both the METAR and Synoptic datasets should be filtered by time to avoid
requesting an unreasonable amount of data. By defining one filter now,
we can use it in both of their data requests to EDEX.

   **Note**: Here we will use the most recent hour as our default
   filter. Try adjusting the timerange and see the difference in the
   final plots.

.. code:: ipython3

    # Filter for the last hour
    lastHourDateTime = datetime.utcnow() - timedelta(minutes = 60)
    start = lastHourDateTime.strftime('%Y-%m-%d %H:%M:%S')
    end = datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S')
    
    beginRange = datetime.strptime( start , "%Y-%m-%d %H:%M:%S")
    endRange = datetime.strptime( end , "%Y-%m-%d %H:%M:%S")
    timerange = TimeRange(beginRange, endRange)
    
    print(timerange)


.. parsed-literal::

    (Nov 11 22 19:00:54 , Nov 11 22 20:00:54 )


Define Common Parameters for Data Requests
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

METAR obs and Synoptic obs share several of the same parameters. By
defining them here, they can be reused for both of the requests and this
makes our code more efficient.

.. code:: ipython3

    shared_params = ["timeObs", "longitude", "latitude", "temperature",
                     "dewpoint", "windDir", "windSpeed", "seaLevelPress",
                     "presWeather", "skyLayerBase"]
    print(shared_params)


.. parsed-literal::

    ['timeObs', 'longitude', 'latitude', 'temperature', 'dewpoint', 'windDir', 'windSpeed', 'seaLevelPress', 'presWeather', 'skyLayerBase']


Define METAR Request
~~~~~~~~~~~~~~~~~~~~

To get METAR data we must use the **obs** datatype. To help limit the
amount of data returned, we will narrow the request by using a
geographic **envelope**, setting the request **parameters**, and using
**timerange** as a time filter.

.. code:: ipython3

    # New metar request
    metar_request = DataAccessLayer.newDataRequest("obs", envelope=envelope)
    
    # metar specifc parameters
    metar_params = ["stationName", "skyCover"]
    # combine all parameters
    all_metar_params = shared_params + metar_params
    # set the parameters on the metar request
    metar_request.setParameters(*(all_metar_params))
    
    print(metar_request)


.. parsed-literal::

    DefaultDataRequest(datatype=obs, identifiers={}, parameters=['timeObs', 'longitude', 'latitude', 'temperature', 'dewpoint', 'windDir', 'windSpeed', 'seaLevelPress', 'presWeather', 'skyLayerBase', 'stationName', 'skyCover'], levels=[], locationNames=[], envelope=<dynamicserialize.dstypes.com.vividsolutions.jts.geom.Envelope.Envelope object at 0x13abe40a0>)


Define Synoptic Request
~~~~~~~~~~~~~~~~~~~~~~~

Similar to the request above, we will limit the amount of data returned
by using a geographic **envelope**, setting the request **parameters**,
and using **timerange** as a time filter.

However, in order to access synoptic observations we will use the
**sfcobs** datatype.

.. code:: ipython3

    # New sfcobs/SYNOP request
    syn_request = DataAccessLayer.newDataRequest("sfcobs", envelope=envelope)
    
    # (sfcobs) uses stationId, while (obs) uses stationName
    syn_params = ["stationId"]
    # combine all parameters
    all_syn_params = shared_params + syn_params
    # set the parameters on the synoptic request
    syn_request.setParameters(*(all_syn_params))
    
    print(syn_request)


.. parsed-literal::

    DefaultDataRequest(datatype=sfcobs, identifiers={}, parameters=['timeObs', 'longitude', 'latitude', 'temperature', 'dewpoint', 'windDir', 'windSpeed', 'seaLevelPress', 'presWeather', 'skyLayerBase', 'stationId'], levels=[], locationNames=[], envelope=<dynamicserialize.dstypes.com.vividsolutions.jts.geom.Envelope.Envelope object at 0x105048bb0>)


`Top <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html>`__

--------------

Get the Data!
-------------

We have already obtained our maps data, but we still have to collect our
observation data.

Get the EDEX Responses
~~~~~~~~~~~~~~~~~~~~~~

.. code:: ipython3

    # METARs data
    metar_response = DataAccessLayer.getGeometryData(metar_request,timerange)
    # function getMetarObs was added in python-awips 18.1.4
    metars = DataAccessLayer.getMetarObs(metar_response)
    print("Found " + str(len(metar_response)) + " METAR records")
    print("\tUsing " + str(len(metars['temperature'])) + " temperature records")
    
    # Synoptic data
    syn_response = DataAccessLayer.getGeometryData(syn_request,timerange)
    # function getSynopticObs was added in python-awips 18.1.4
    synoptic = DataAccessLayer.getSynopticObs(syn_response)
    print("Found " + str(len(syn_response)) + " Synoptic records")
    print("\tUsing " + str(len(synoptic['temperature'])) + " temperature records")


.. parsed-literal::

    Found 4116 METAR records
    	Using 179 temperature records
    Found 259 Synoptic records
    	Using 63 temperature records


Extract Plotting Data
~~~~~~~~~~~~~~~~~~~~~

.. code:: ipython3

    # Pull all necessary plotting information for the metar data
    metars_data = extract_plotting_data(metars, 'obs')
    print(str(len(metars_data['stid'])) + " METARs stations")
    
    # Pull all necessary plotting information for the synoptic data
    synoptic_data = extract_plotting_data(synoptic, 'sfcobs')
    print(str(len(synoptic_data['stid'])) + " Synoptic stations")


.. parsed-literal::

    179 METARs stations
    63 Synoptic stations


`Top <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html>`__

--------------

Plot the Data
-------------

Draw the Region
~~~~~~~~~~~~~~~

Here we will draw our region by using the **states** polygons we
retreived from EDEX `earlier in this
example <#Maps-Request-and-Response>`__. To create this plot we use the
`make_map() <#Function:-make_map()>`__ function which also adds lines of
latitude and longitude for additional context.

.. code:: ipython3

    # Create the figure and axes used for the plot
    fig, ax = make_map(bbox=bbox)
    # Create a feature based off our states polygons
    shape_feature = ShapelyFeature(states,ccrs.PlateCarree(), 
                        facecolor='none', linestyle="-",edgecolor='#000000',linewidth=2)
    ax.add_feature(shape_feature)




.. parsed-literal::

    <cartopy.mpl.feature_artist.FeatureArtist at 0x13b2ae5e0>




.. image:: Regional_Surface_Obs_Plot_files/Regional_Surface_Obs_Plot_42_1.png


Plot METAR Data
~~~~~~~~~~~~~~~

On the same axes (**ax**) and figure (**fig**) plot the METAR data.

.. code:: ipython3

    # Create a title for the plot
    title = str(metar_response[-1].getDataTime()) + " | METAR Surface Obs | " + edexServer
    # Plot the station information for METARs data
    plot_data(metars_data, title, ax, 'obs')
    # Display the figure
    fig




.. image:: Regional_Surface_Obs_Plot_files/Regional_Surface_Obs_Plot_44_0.png



Plot Synoptic Data
~~~~~~~~~~~~~~~~~~

On a new axes and figure (**ax_syn**, **fig_syn**) plot the map and
synoptic data.

.. code:: ipython3

    # Create a new figure and axes for the synoptic data
    fig_syn, ax_syn = make_map(bbox=bbox)
    # Create the states feature from the polygons
    shape_feature = ShapelyFeature(states,ccrs.PlateCarree(), 
                        facecolor='none', linestyle="-",edgecolor='#000000',linewidth=2)
    ax_syn.add_feature(shape_feature)
    # Create a title for the figure
    title = str(syn_response[-1].getDataTime()) + " | SYNOP Surface Obs | " + edexServer
    # Draw the synoptic data
    plot_data(synoptic_data, title, ax_syn, 'sfcobs')



.. image:: Regional_Surface_Obs_Plot_files/Regional_Surface_Obs_Plot_46_0.png


Plot both METAR and Synoptic Data
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Add the synoptic data to our first axes and figure (**ax**, **fig**)
that already contains our map and METARs data.

.. code:: ipython3

    # Create a title for both the METAR and Synopotic data
    title = str(syn_response[-1].getDataTime()) + " | METAR & Synoptic Surface Obs | " + edexServer
    # Draw the synoptic on the first axes that already has the metar data
    plot_data(synoptic_data, title, ax, 'sfcobs')
    # Display the figure
    fig




.. image:: Regional_Surface_Obs_Plot_files/Regional_Surface_Obs_Plot_48_0.png



`Top <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html>`__

--------------

See Also
--------

-  `Aviation Weather Center Static METAR Plots
   Information <https://www.aviationweather.gov/metar/help?page=plot>`__

Related Notebooks
~~~~~~~~~~~~~~~~~

-  `Metar Station Plot with
   MetPy <http://unidata.github.io/python-awips/examples/generated/METAR_Station_Plot_with_MetPy.html>`__
-  `Map Resources and
   Topography <http://unidata.github.io/python-awips/examples/generated/Map_Resources_and_Topography.html>`__

Additional Documentation
~~~~~~~~~~~~~~~~~~~~~~~~

**python-awips:**

-  `DataAccessLayer.changeEDEXHost() <http://unidata.github.io/python-awips/api/DataAccessLayer.html#awips.dataaccess.DataAccessLayer.changeEDEXHost>`__
-  `DataAccessLayer.newDataRequest() <http://unidata.github.io/python-awips/api/DataAccessLayer.html#awips.dataaccess.DataAccessLayer.newDataRequest>`__
-  `IDataRequest <http://unidata.github.io/python-awips/api/IDataRequest.html>`__
-  `DataAccessLayer.getGeometryData <http://unidata.github.io/python-awips/api/PyGeometryData.html>`__

**datetime:**

-  `datetime.datetime <https://docs.python.org/3/library/datetime.html#datetime-objects>`__
-  `datetime.utcnow() <https://docs.python.org/3/library/datetime.html?#datetime.datetime.utcnow>`__
-  `datetime.timedelta <https://docs.python.org/3/library/datetime.html#timedelta-objects>`__
-  `datetime.strftime() and
   datetime.strptime() <https://docs.python.org/3/library/datetime.html#strftime-and-strptime-behavior>`__

**numpy:**

-  `np.array <https://numpy.org/doc/stable/reference/generated/numpy.array.html>`__

**cartopy:**

-  `cartopy projection
   list <https://scitools.org.uk/cartopy/docs/v0.14/crs/projections.html?#cartopy-projection-list>`__

**matplotlib:**

-  `matplotlib.pyplot() <https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.html>`__
-  `matplotlib.pyplot.figure() <https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.figure.html>`__
-  `ax.set_extent <https://matplotlib.org/stable/api/image_api.html?highlight=set_extent#matplotlib.image.AxesImage.set_extent>`__
-  `ax.set_title <https://matplotlib.org/stable/api/_as_gen/matplotlib.axes.Axes.set_title.html>`__

**metpy:**

-  `metpy.calc.wind_components <https://unidata.github.io/MetPy/latest/api/generated/metpy.calc.wind_components.html>`__
-  `metpy.plots.StationPlot() <https://unidata.github.io/MetPy/latest/api/generated/metpy.plots.StationPlot.html>`__
-  `metpy.plots.StationPlotLayout() <https://unidata.github.io/MetPy/latest/api/generated/metpy.plots.StationPlotLayout.html>`__
-  `metpy.units <https://unidata.github.io/MetPy/latest/api/generated/metpy.units.html>`__

`Top <https://unidata.github.io/python-awips/examples/generated/Regional_Surface_Obs_Plot.html>`__

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